The FIA's investigation into Renault runs even deeper than the sensational rumour that Nelson Piquet was told to crash on purpose during the 2008 Singapore grand prix.

The FIA's investigation into Renault runs even deeper than the sensational rumour that Nelson Piquet was told to crash on purpose during the 2008 Singapore grand prix.

The Independent newspaper in Britain quoted a source within the sport's governing body as saying "other issues above and beyond Singapore are also to be looked at".

The investigations reportedly began at Spa-Francorchamps last weekend, with engineering boss Pat Symonds and Fernando Alonso among "senior Renault figures" interviewed multiple times, the source added.

The Daily Express newspaper, reporting that team boss Flavio Briatore was also interviewed by a lawyer in Belgium, said Renault executives have already denied the Piquet claims to the FIA.

"Several other engineering staff were also questioned", the newspaper added, while "data and transmission recordings have been removed for examination".

Two men historically close to the French owned team however have questioned whether the race-fixing rumours are true.

Denis Chevrier left the team over the winter, but he was still Renault's engine chief in Singapore last year.

"In my personal capacity I did not have knowledge of the strategy during the 2008 grand prix of Singapore," he told French radio RMC, "but I can ensure you that if this is true then it was in radical opposition to the attitude of Renault."

From a driver's perspective, Franck Montagny - a Renault F1 tester earlier this decade - said he "did not believe" the claims could be true.

"Even when you are asked to let someone pass it is annoying," he said, "but to be made to deliberately have an accident is really something else."

Montagny called the rumours "science fiction" and doubted that Briatore could have asked one of his drivers to crash.

"Not even in a dream," the Frenchman said in an interview with 20minutes.fr. "Nobody can give instructions like that; I've never heard anything like that in formula one."